1. Field of the Invention
This invention relates to brake booster assemblies or servo motors of the type used to operate power-assisted brakes.
2. Description of the Prior Art
Known brake booster assemblies usually consist of a housing having a power piston and diaphragm forming a movable wall for reciprocable movement in the housing or container, the movable wall dividing the housing into two compartments. A pressure differential across the movable wall causes movement of the wall. A control valve operated by the operator of the vehicle regulates the degree of vacuum or subatmospheric pressure established at one side of the movable wall. The movable wall is connected with the master cylinder of the hydraulic brake system of the motor vehicle so that when a pressure differential is effective on the movable wall, i.e. power movement of the wall is produced, hydraulic fluid is displaced from the master cylinder into the hydraulic brake system to apply the brakes of the vehicle.
In the past, the brake master cylinder has been bolted to the front end wall of the housing and the rear end wall of the housing has been in turn bolted to a dash board of the vehicle body in order to install the brake booster assembly in the vehicle together with the master cylinder. In this arrangement, a reactional force developed in the brake master cylinder when in operation is transmitted through the housing to the dash board. This is considered a defect in that, the arrangement necessitates a heavy gauge sheet metal for the housing sufficiently to avoid any tendency of strain of the housing due to the reactional force.